From 500767a0fb7052d91435391af0ae1908a4ecae9f Mon Sep 17 00:00:00 2001
From: Sam Brannen <104798+sbrannen@users.noreply.github.com>
Date: Fri, 26 Jan 2024 14:46:05 +0100
Subject: [PATCH] Annotate core functional SPIs in SpEL with
 @FunctionalInterface
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Prior to this commit, only the MethodFilter and ConstructorResolver
functional SPIs in the org.springframework.expression package were
annotated with @⁠FunctionalInterface.

For consistency, this commit designates each of the following
functional SPIs in that package as a @⁠FunctionalInterface as well.

- BeanResolver
- ConstructorExecutor
- MethodExecutor
- MethodResolver

Closes gh-32135
---
 .../main/java/org/springframework/expression/BeanResolver.java   | 1 +
 .../java/org/springframework/expression/ConstructorExecutor.java | 1 +
 .../main/java/org/springframework/expression/MethodExecutor.java | 1 +
 .../main/java/org/springframework/expression/MethodResolver.java | 1 +
 4 files changed, 4 insertions(+)

diff --git a/spring-expression/src/main/java/org/springframework/expression/BeanResolver.java b/spring-expression/src/main/java/org/springframework/expression/BeanResolver.java
index decb1e0ca8b..f6fa6e37f16 100644
--- a/spring-expression/src/main/java/org/springframework/expression/BeanResolver.java
+++ b/spring-expression/src/main/java/org/springframework/expression/BeanResolver.java
@@ -25,6 +25,7 @@ package org.springframework.expression;
  * @author Andy Clement
  * @since 3.0.3
  */
+@FunctionalInterface
 public interface BeanResolver {
 
 	/**
diff --git a/spring-expression/src/main/java/org/springframework/expression/ConstructorExecutor.java b/spring-expression/src/main/java/org/springframework/expression/ConstructorExecutor.java
index 5af02af1ee4..363506b951f 100644
--- a/spring-expression/src/main/java/org/springframework/expression/ConstructorExecutor.java
+++ b/spring-expression/src/main/java/org/springframework/expression/ConstructorExecutor.java
@@ -37,6 +37,7 @@ package org.springframework.expression;
  * @see ConstructorResolver
  * @see MethodExecutor
  */
+@FunctionalInterface
 public interface ConstructorExecutor {
 
 	/**
diff --git a/spring-expression/src/main/java/org/springframework/expression/MethodExecutor.java b/spring-expression/src/main/java/org/springframework/expression/MethodExecutor.java
index 170914e456f..6d717cd4b00 100644
--- a/spring-expression/src/main/java/org/springframework/expression/MethodExecutor.java
+++ b/spring-expression/src/main/java/org/springframework/expression/MethodExecutor.java
@@ -36,6 +36,7 @@ package org.springframework.expression;
  * @see MethodResolver
  * @see ConstructorExecutor
  */
+@FunctionalInterface
 public interface MethodExecutor {
 
 	/**
diff --git a/spring-expression/src/main/java/org/springframework/expression/MethodResolver.java b/spring-expression/src/main/java/org/springframework/expression/MethodResolver.java
index 9d8c0bbaf06..9fb9137c8e4 100644
--- a/spring-expression/src/main/java/org/springframework/expression/MethodResolver.java
+++ b/spring-expression/src/main/java/org/springframework/expression/MethodResolver.java
@@ -34,6 +34,7 @@ import org.springframework.lang.Nullable;
  * @see MethodExecutor
  * @see ConstructorResolver
  */
+@FunctionalInterface
 public interface MethodResolver {
 
 	/**